<!DOCTYPE html>
<html>
<head>
	<title></title>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
<form>
	用户名：<input type="text" name="test" id="test" disabled="disabled">
	<label><input id= "abc" name="Fruit" type="radio" value="" onclick="fun()" checked />苹果 </label> 
	<label><input name="Fruit" type="radio" value="" onclick="fun1()" />桃子 </label> 
	<label><input name="Fruit" type="radio" value="" />香蕉 </label> 
	<label><input name="Fruit" type="radio" value="" />梨 </label> 
	<label><input name="Fruit" type="radio" value="" />其它 </label> 
</form>
<script type="text/javascript">
function fun() {
	 /*document.getElementById("test").style.desabled="desabled";*/
	  document.getElementById("test").disabled=true;
}
function fun1() {
	 /*document.getElementById("test").style.desabled="desabled";*/
	  document.getElementById("test").disabled=false;
}
</script>
</body>
</html>